Ahoy Maties! Season 5 brought us a new commendation section in the Bilge Rats portion of your journal (Buried Treasures). With it came several achievements to plunder!
This particular achievement tasks you with uncovering 25 valuable treasures buried by other pirate crews. In fact, they don't need to be valuable at all, and can be any buried item from empty cannon ball crates, buried chickens, and actual loot. There are new quest maps than can be found pinned to a quest board on all the outpost docks and seapost docks as well. If you look at these maps you can purchase up to 5 maps made my other pirates per in game day (every 24 minutes). Even if there aren't maps created by actual users, the game will always have at least two AI generated maps per region of the game so there will always be maps to purchase. Try to purchase maps that are located on the same island to make this go faster. Once you have dug up 25 items (you don't even need to turn them in), the achievement and commendation will unlock!
Below is also a video guide I made if you prefer video!
See you on the Seas!
-Damron Out